1. The Louisiana Purchase: On July 13, 1803, Louisiana officially became part of the United States after the Louisiana Purchase. The deal was signed on April 30 of that year, but it was on this day that the transfer of the territory took place.

2. Battle of Baton Rouge: On July 13, 1862, the Battle of Baton Rouge took place during the Civil War. Confederate soldiers attempted to capture the city, but were unsuccessful. The Union army was able to hold their ground and prevent the Confederates from advancing further into Louisiana.

3. Huey Long Assassination: On July 13, 1935, Huey P. Long was shot and killed in the Louisiana State Capitol building in Baton Rouge. Long was a governor and senator from Louisiana, known for his controversial political tactics and populist views.

4. Hurricane Betsy: On July 13, 1965, Hurricane Betsy made landfall in Louisiana, causing extensive damage to the city of New Orleans and surrounding areas. The storm was responsible for 76 deaths and $1.42 billion in damage (adjusted for inflation).

5. Cajun Music Legend Dies: On July 13, 1992, Cajun music legend Iry LeJeune died at the age of 45. LeJeune was a master of the accordion and an influential figure in the development of Cajun music. His music continues to be celebrated and performed throughout Louisiana and beyond.